Remove auto play component and reuse Video preview gUM

...orts/api/users-settings/server/methods/addUserSettings.js

bigbluebutton-html5/imports/ui/components/app/component.jsx

...luebutton-html5/imports/ui/components/audio/container.jsx

...n-html5/imports/ui/components/video-preview/component.jsx

...n-html5/imports/ui/components/video-preview/container.jsx

...i/components/video-provider/auto-play-video/component.jsx

...i/components/video-provider/auto-play-video/container.jsx

...s/ui/components/video-provider/video-button/component.jsx

...s/ui/components/video-provider/video-button/container.jsx

bigbluebutton-html5/private/config/settings.yml